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Related papers: Quantum control for high-fidelity multi-qubit gate…

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Coherent control errors, for which ideal Hamiltonians are perturbed by unknown multiplicative noise terms, are a major obstacle for reliable quantum computing. In this paper, we present a framework for analyzing the robustness of quantum…

Quantum Physics · Physics 2024-12-04 Julian Berberich , Daniel Fink , Christian Holm

A single-shot Toffoli, or controlled-controlled-NOT, gate is desirable for classical and quantum information processing. The Toffoli gate alone is universal for reversible computing and, accompanied by the Hadamard gate, forms a universal…

Quantum Physics · Physics 2015-05-21 Ehsan Zahedinejad , Joydip Ghosh , Barry C. Sanders

In this paper, we demonstrate that optimal control algorithms can be used to speed up the implementation of modules of quantum algorithms or quantum simulations in networks of coupled qubits. The gain is most prominent in realistic cases,…

Quantum Physics · Physics 2008-12-20 T. Schulte-Herbrueggen , A. K. Spoerl , N. Khaneja , S. J. Glaser

We study the robustness of the evolution of a quantum system against small uncontrolled variations in parameters in the Hamiltonian. We show that the fidelity susceptibility, which quantifies the perturbative error to leading order, can be…

Quantum Physics · Physics 2024-05-09 Pablo M. Poggi , Gabriele De Chiara , Steve Campbell , Anthony Kiely

This work studies the feasibility of optimal control of high-fidelity quantum gates in a model of interacting two-level particles. One particle (the qubit) serves as the quantum information processor, whose evolution is controlled by a…

Quantum optimal control is a technique for controlling the evolution of a quantum system and has been applied to a wide range of problems in quantum physics. We study a binary quantum control optimization problem, where control decisions…

Quantum Physics · Physics 2024-10-15 Xinyu Fei , Lucas T. Brady , Jeffrey Larson , Sven Leyffer , Siqian Shen

Quantum optimal control for gate optimization aims to provide accurate, robust, and fast pulse sequences to achieve gate fidelities on quantum systems below the error correction threshold. Many methods have been developed and successfully…

Quantum Physics · Physics 2025-06-05 Dirk Heimann , Felix Wiebe , Tahereh Abad , Elie Mounzer , Tangyou Huang , Frank Kirchner , Shivesh Kumar

The central challenge of quantum computing is implementing high-fidelity quantum gates at scale. However, many existing approaches to qubit control suffer from a scale-performance trade-off, impeding progress towards the creation of useful…

We examine the effectiveness and resilience of achieving quantum gates employing three approaches stemming from quantum control methods: counterdiabatic driving, Floquet engineering, and inverse engineering. We critically analyse their…

Quantum Physics · Physics 2023-08-30 Eoin Carolan , Barış Çakmak , Steve Campbell

In this paper, we present efficient quantum algorithms that are exponentially faster than classical algorithms for solving the quantum optimal control problem. This problem involves finding the control variable that maximizes a physical…

Quantum Physics · Physics 2023-10-02 Xiantao Li , Chunhao Wang

Quantum optimal control is a promising approach to improve the accuracy of quantum gates, but it relies on complex algorithms to determine the best control settings. CPU or GPU-based approaches often have delays that are too long to be…

In this paper, we study the optimal simulation of three-qubit unitary by using two-qubit gates. First, we give a lower bound on the two-qubit gates cost of simulating a multi-qubit gate. Secondly, we completely characterize the two-qubit…

Quantum Physics · Physics 2013-01-17 Nengkun Yu , Mingsheng Ying

Developing optimal strategies to calibrate quantum processors for high-fidelity operation is one of the outstanding challenges in quantum computing today. Here, we demonstrate multiple examples of high-fidelity operations achieved using a…

The precise implementation and manipulation of quantum gates is key to extracting advantages from future quantum technologies. Achieving this requires very accurate control over the quantum system. If one has complete knowledge about a…

Quantum Physics · Physics 2025-03-21 Anirban Dey , Mattias T. Johnsson , Daniel Burgarth

We experimentally demonstrate fast and high-fidelity geometric control of a quantum system with the most brachistochrone method on hybrid spin registers in diamond. Based on the time-optimal universal geometric control, single geometric…

Quantum Physics · Physics 2021-05-13 Yang Dong , Ce Feng , Yu Zheng , Xiang-Dong Chen , Guang-Can Guo , Fang-Wen Sun

Quantum computation is based on implementing selected unitary transformations which represent algorithms. A generalized optimal control theory is used to find the driving field that generates a prespecified unitary transformation. The…

Quantum Physics · Physics 2009-11-07 Jose P. Palao , Ronnie Kosloff

The native gate set is fundamental to the performance of quantum devices, as it governs the accuracy of basic quantum operations and dictates the complexity of implementing quantum algorithms. Traditional approaches to extending gate sets…

In this paper, we examine various software and hardware strategies for implementing high-fidelity controlled-Z gate in the large-scale quantum system by solving the system's Hamiltonian with the Lindblad master equation. First, we show that…

Quantum Physics · Physics 2022-12-09 Dowon Baek , Seong Hyeon Park , Suhwan Choi , Chanwoo Yoo , Seungyong Hahn

Simple, precise, and robust control is demanded for operating a large quantum information processor. However, existing routes to high-fidelity quantum control rely heavily on arbitrary waveform generators that are difficult to scale up.…

Quantum Physics · Physics 2022-09-21 Qi-Ming Chen , Herschel Rabitz , Re-Bing Wu

Control of quantum systems via time-varying external fields optimized to maximize a fidelity measure at a given time is a mainstay in modern quantum control. However, save for specific systems, current analysis techniques for such quantum…

Quantum Physics · Physics 2024-01-10 Sean Patrick O'Neil , Edmond Jonckheere , Sophie Schirmer